Anyone got a Metrel 3125 Eurotest Combo

[liddley]

Dont understand instructions clearly, another forum member has just forwarded me the instructions and still confused?

When taking Ze reading the meter only seems to show the pscc value but not pfc value.

As I read the instructions it only seems to give you the pfc option on the Zs(Zloop) setting and pscc on the Ze(Zline) ?? confused me. Can anyone tell me otherwise or am I misunderstanding the instruction manual.
(probably the latter)

 

[Richard Burns]

When you measure the external earth fault loop impedance, ze, using the Zloop function you are measuring the resistance between Line and Earth at the origin.
When you measure the earth fault loop impedance, zs, of a circuit with an RCD in place you use the zRCD function, this is again measuring the resistance between Line and Earth but with the tested circuit included.

In both these cases the Isc value given is the Prospective Earth Fault Current, PEFC

When you measure the prospective short circuit current using the zLine function you are measuring the resistance between Line and Neutral and the Isc value given is the Prospective short circuit current, PSCC.

The highest of the PEFC and PSCC is the Prospective Fault Current, PFC.

 

[MarkieSparkie]

Liddley remember GN3 requires:- Ze is measured with the earthing conductor disconnected from the MET. Whereas Zs, PSCC and PEFC are all measured with the earthing conductor connected to the MET.
In practice, when testing for Ze with the earth conductor disconnected from the MET your MFT will provide you with readings for both Ze and 'PEFC' from this test, however, the 'PEFC' reading should be ignored. When the earthing conductor is reconnected to MET the test is repeated this time ignoring the 'Ze' value, which is likely to be lower than previous one due to parallel earth paths, consequently PEFC is likely to be higher and the worst case value which should be noted and compared with PSCC later in order to determine the PFC to be recorded on the paperwork.